Vertical transmission of Toxoplasma gondii in naturally infected ewes in the semiarid region of Brazil.

To evaluate transplacental transmission of Toxoplasma gondii in naturally infected ewes, blood samples were collected from 55 pregnant ewes and their offspring, before ingestion of colostrum. From 16 offspring of positive ewes and nine offspring from negative ewes, blood samples were obtained after 48 h and 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. T. gondii antibodies were detected in serum samples using the indirect fluorescence antibody test (IFAT ≥ 64). Four of the 30 positive ewes (13.3 %) had offspring positive for T. gondii before ingesting colostrum (vertical transmission). The colostrum antibody titers decreased every week, and only 20 % (2/10) of the lambs in continued to present detectable antibody titers until day 56 after birth. Therefore, vertical transmission of T. gondii in lambs was indication of occur and is an important route for transferring and maintaining the agent in sheep herds in the Brazilian semiarid region.